When I first heard that the Red Sox signed Adrian Beltre to a one-year, $9 million contract with a 2011 player option for $5 million, my first thought was that it was a perfect deal for both parties involved. On the one hand, the Red Sox fill a gaping hole at third base, but only temporarily so they still give themselves the opportunity to make a play for Adrian Gonzalez later on. On the other hand, Adrian Beltre gives himself an opportunity to prosper in a hitter-friendly environment so that he can sign that last big contract before he retires.

Beltre’s decision to sign such a contract with the Red Sox should tell us two things: (1) the market out there was nowhere close to the four-year, $50 million contract he and Boras set out to get and (2) he thinks that Fenway Park will help him put up good enough offensive numbers to get a three-year deal next offseason.

With the signing, the Red Sox complete their defensive overhaul for 2010, one that included the signings of Mike Cameron and Beltre, the loss of Jason Bay, and the benching of both Mike Lowell and Jason Varitek. I have said before that it was more important for the Red Sox to improve their defense rather than focus on their offense.

Their defense now projects to look like this in 2010 with (UZR ratings):

For those counting, that’s a +60.5 rating as compared to their -10.5 rating in 2009 (I only used players that played significant time at each position for the Red Sox in 2009). The importance here is that Kevin Youkilis gets to stay at first base rather than third, where he posted a -1.6 UZR last season. Also, Beltre should make Scutaro’s job at shortstop a lot easier, because he can get to balls that normal third basemen can’t.

That kind of difference in the defense will not only take a lot of pressure off their starting pitching, but the offense won’t have the same pressure it did last year to score five runs per game. We might be looking at the best defense in the majors next season.

So why don’t we look at what Adrian Beltre brings to this team?

Scouting Adrian Beltre

Defense

We all know what a great defensive third baseman he is, but just how good is he? He won the AL Gold Glove award in both 2007 and 2008, but the praises from Tampa Bay Rays’ manager Joe Maddon really tell the story.

“[Beltre is] clearly the best [third baseman] I’ve ever seen in person,” said Tampa Bay Rays manager Joe Maddon. “I think [Evan Longoria] is good, I used to think Scott Brosius was really good. … [Eric] Chavez was good, but Beltre was stupid good. I think Beltre is the best who I’ve ever seen with my two eyes – defender, not just third baseman, but defense.”

So we are not only talking about the best fielding third baseman in the game right now, but possibly the best of all time. Red Sox fans thought they had it good with Mike Lowell manning the hot corner, but I have a feeling they are in for a treat in 2010.

Offense

As for his offense, people look at his .325 career on-base percentage and immediately dismiss him. How does he fit on a team that praises the J.D. Drew’s and Kevin Youkilis’ of the world? Well, for starters, Beltre’s offensive numbers should improve now that he is in a hitter-friendly ballpark as opposed to Safeco Field, which is known for knocking right handed hitters down a peg or two.

In 2009, Safeco Field was 21st in the majors in runs scored and 24th in home runs while Fenway Park was ranked eighth and 21st in those same categories.

Want more proof? Consider Beltre’s home/road splits since he signed with the Mariners in 2005:

Home (353 games): .254 BA, 116 extra-base hits, 174 RBI

Away (362 games): .277 BA, 167 extra-base hits, 222 RBI

That’s a 23-point difference in batting average and 51 more extra base hits in just nine more games. Beltre, a right-handed pull hitter, should see his offensive numbers improve at Fenway Park as it is more conducive to his style of hitting. He is either going to bat sixth between David Ortiz and J.D. Drew or eighth between J.D. Drew and Marco Scutaro/Jacoby Ellsbury (due to Francona’s love of alternating lefties and righties). Either way, it sure beats batting with the likes of Franklin Gutierrez and Russell Branyan.

Injury Risk?

Of course, like most players, Beltre does come with some risk. He has battled shoulder injuries for over a year now and played in just 111 games last season, which was his lowest total since becoming a full-time starter in 1999. If he can fully recover from surgery and be productive for 145+ games in 2010, the Red Sox will not only greatly upgrade their defense, but will get a formidable back-of-the-lineup hitter as well.

The infield defense last year as a whole was rated 17 runs below average, thanks to the horrible defense at SS and 3B. The outfield as a whole was 6 runs below average, mostly because Ellsbury had a bad year in CF, playing too deep in my opinion, with a poor arm for CF.

Overall, the team was 23 runs below a team of league average defenders.

For this year, Scutaro was a +12 SS last year, Beltre was a +22 3B. Cameron was a +3 CF. In 2008, Ellsbury was rated as a +5 LF. If everyone repeats their numbers this year, the Sox defense would be:

Which comes to 68 runs better than average as a group. Or 91 runs better than last year’s group. Last year, the Sox allowed 736 runs.

IF the defense really is 91 runs better than last year, even if the pitching was exactly the same overall, they’d allow 645 runs. The runs allowed per game would drop from 4.54 to 3.98, which would probably be the best in the game.

Of course there are a lot of ifs here, and some people will reject the defensive numbers for whatever reason. But I think it’s very reasonable to expect the Red Sox to give up significantly fewer runs than last year. And Beltre’s a big part of that.

Now the offense is a whole different matter. And just adding Scutaro while moving Youkilis to third and keeping Kotchman at first would’ve upgraded the infield defense from horrible to good without adding Beltre.

The idea is that Beltre instead upgrades it from horrible to one of the best in the game. Should be interesting to see if that happens.

The guy does have great range, good hands, and an amazing arm, check out his highlights:

If you think Beltre is even remotely close to Brooks Robinson and thus could be considered in the running for greatest 3rd baseman of all time, you are out of your mind. Beltre is a great fielder, no doubt, easily in the top 3 or (Rolen, Longoria are the other two), but none of them are as good as Robinson.